Procedures for disarming an explosive device should minimize the potential risk of accidentally detonating the explosive material contained within the device. The explosive device often includes associated electronic circuitry for detonating the explosive. A proven disarming technique is deactivating or destroying this circuitry before it can detonate the explosive. Because such circuitry is often sensitive to tampering, the disarming procedure should deactivate the circuitry within a short time after any contact with or movement of the device has been initiated.
One procedure for disarming an electronic explosive device is to fire a projectile into the electronic circuitry of the device. The projectile should preferably pierce the device enclosure and deactivate the electronic circuitry before the circuitry can detonate the explosive material. Typically, a gun assembly is used to fire the projectile at the device enclosure. For example, a charge of smokeless gunpowder, ignited by an electric match, may impart the required momentum to the projectile.
One problem with this procedure is that the electric match can prematurely fire the gun assembly. One cause of premature firing is stray electromagnetic energy, such as radio waves, which may provide a premature ignition signal to the match. Premature firing, particularly before the gun is properly aimed or mounted, can cause damage to the gun assembly as well as to other objects in close proximity to the gun assembly.